<header>What domain to use in outbound mail</header>

<center><tt>myorigin</tt></center>
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You specify the domain that appears in mail that is posted on this machine. The
default configuration of Postfix is to use the local machine name,
<tt>hostname</tt>.

<p>

Unless you are running a really small site, you probably want to change that
into <tt>domainname</tt>, which defaults to the parent domain of the machine
name.

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